/*
 * @(#) DateConverter.java
 *
 * Copyright 2002 - 2003 JIDE Software. All rights reserved.
 */
package com.element.converter.impl;

import com.element.converter.ConverterContext;
import com.element.converter.ObjectConverter;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

/**
 * Converter which converts Date to String and converts it back.
 */
public class DateConverter extends ObjectConverter {

	public static final ConverterContext DATETIME_CONTEXT = new ConverterContext("DateTime");
	public static final ConverterContext TIME_CONTEXT = new ConverterContext("Time");
	public static final ConverterContext DATE_CONTEXT = new ConverterContext("Date");

	private DateFormat _shortFormat = SimpleDateFormat.getDateInstance(DateFormat.SHORT);
	private DateFormat _mediumFormat = SimpleDateFormat.getDateInstance(DateFormat.MEDIUM);
	private DateFormat _longFormat = SimpleDateFormat.getDateInstance(DateFormat.LONG);

	private DateFormat _defaultFormat = SimpleDateFormat.getDateInstance(DateFormat.DEFAULT);

	private DateFormat _shortDatetimeFormat = SimpleDateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT);
	private DateFormat _mediumDatetimeFormat = SimpleDateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
	private DateFormat _longDatetimeFormat = SimpleDateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG);

	private DateFormat _defaultDatetimeFormat = SimpleDateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT);

	private DateFormat _shortTimeFormat = SimpleDateFormat.getTimeInstance(DateFormat.SHORT);
	private DateFormat _mediumTimeFormat = SimpleDateFormat.getTimeInstance(DateFormat.MEDIUM);
	private DateFormat _longTimeFormat = SimpleDateFormat.getTimeInstance(DateFormat.LONG);

	private DateFormat _defaultTimeFormat = SimpleDateFormat.getTimeInstance(DateFormat.DEFAULT);


	/**
	 * Creates a DateConverter.
	 */
	public DateConverter() {
	}

	/**
	 * Converts the object to String. The object can be a Calendar, a Date or a Number. As long as the DateFormat can
	 * format it correctly, it will be converted to a String. If the object is already a String, we will return it
	 * directly as it is.
	 *
	 * @param object  the object to be converted
	 * @param context the converter context.
	 * @return the string
	 */
	synchronized public String toString(Object object, ConverterContext context) {
		if (object == null) {
			return "";
		} else {
			TimeZone timeZone;
			if (object instanceof Calendar) {
				timeZone = ((Calendar) object).getTimeZone();
				object = ((Calendar) object).getTime();
			} else if (object instanceof Date) {
				Calendar cal = Calendar.getInstance();
				cal.setTime(((Date) object));
				timeZone = cal.getTimeZone();
			} else {
				timeZone = TimeZone.getDefault();
			}

			if (object instanceof Date || object instanceof Number) {
				if (context != null && context.getUserObject() instanceof DateFormat) {
					return ((DateFormat) context.getUserObject()).format(object);
				} else if (DATETIME_CONTEXT.equals(context)) {
					_defaultDatetimeFormat.setTimeZone(timeZone);
					return _defaultDatetimeFormat.format(object);
				} else if (TIME_CONTEXT.equals(context)) {
					_defaultTimeFormat.setTimeZone(timeZone);
					return _defaultTimeFormat.format(object);
				} else {
					_defaultFormat.setTimeZone(timeZone);
					return _defaultFormat.format(object);
				}
			} else if (object instanceof String) {
				return (String) object;
			} else {
				return null;
			}
		}
	}

	/**
	 * Converts from a String to a Date.
	 *
	 * @param string  the string to be converted.
	 * @param context the context. It could be DATETIME_CONTEXT, DATE_CONTEXT or TIME_CONTEXT.
	 * @return the Date. If the string is null or empty, null will be returned. If the string cannot be parsed as a
	 * date, the string itself will be returned.
	 */
	synchronized public Object fromString(String string, ConverterContext context) {
		if (string == null) {
			return null;
		}
		string = string.trim();
		if (string.length() == 0) {
			return null;
		}

		try {
			Object userObject = context != null ? context.getUserObject() : null;
			if (userObject instanceof DateFormat) {
				return ((DateFormat) userObject).parse(string);
			} else if (DATETIME_CONTEXT.equals(context)) {
				return _defaultDatetimeFormat.parse(string);
			} else if (TIME_CONTEXT.equals(context)) {
				return _defaultTimeFormat.parse(string);
			} else {
				return _defaultFormat.parse(string);
			}
		} catch (ParseException e1) { // if current formatter doesn't work try those default ones.
			if (DATETIME_CONTEXT.equals(context)) {
				try {
					return _shortDatetimeFormat.parse(string);
				} catch (ParseException e2) {
					try {
						return _mediumDatetimeFormat.parse(string);
					} catch (ParseException e3) {
						try {
							return _longDatetimeFormat.parse(string);
						} catch (ParseException e4) {
							// null
						}
					}
				}
			} else if (TIME_CONTEXT.equals(context)) {
				try {
					return _shortTimeFormat.parse(string);
				} catch (ParseException e2) {
					try {
						return _mediumTimeFormat.parse(string);
					} catch (ParseException e3) {
						try {
							return _longTimeFormat.parse(string);
						} catch (ParseException e4) {
							return string;  // nothing works just return null so that old value will be kept.
						}
					}
				}
			} else {
				try {
					return _shortFormat.parse(string);
				} catch (ParseException e2) {
					try {
						return _mediumFormat.parse(string);
					} catch (ParseException e3) {
						try {
							return _longFormat.parse(string);
						} catch (ParseException e4) {
							// null
						}
					}
				}
			}
		}

		// try other default formats
		String[] formatStrings = {"yyyy-mm-dd", "yy-mm-dd", "yyyymmdd", "yymmdd", "dd-MMM-yy", "dd-MMM-yyyy"};
		SimpleDateFormat sdf;
		for (String formatString : formatStrings) {
			try {
				sdf = new SimpleDateFormat(formatString);
				return sdf.parse(string);
			} catch (ParseException ex) {
				// break;
			}
		}
		return string;  // nothing works just return null so that old value will be kept.
	}

	/**
	 * Gets DefaultFormat to format an calendar.
	 *
	 * @return DefaultFormat
	 */
	public DateFormat getDefaultFormat() {
		return _defaultFormat;
	}

	/**
	 * Sets DefaultFormat to format an calendar.
	 *
	 * @param defaultFormat the new default date format
	 */
	public void setDefaultFormat(DateFormat defaultFormat) {
		_defaultFormat = defaultFormat;
	}

	/**
	 * Gets DefaultTimeFormat to format an calendar. This is used only when context is {@link #TIME_CONTEXT}.
	 *
	 * @return DefaultTimeFormat
	 */
	public DateFormat getDefaultTimeFormat() {
		return _defaultTimeFormat;
	}

	/**
	 * Sets DefaultTimeFormat to format an calendar. This is used only when context is {@link #TIME_CONTEXT}.
	 *
	 * @param defaultTimeFormat the new default time format
	 */
	public void setDefaultTimeFormat(DateFormat defaultTimeFormat) {
		_defaultTimeFormat = defaultTimeFormat;
	}

	/**
	 * Gets DefaultDatetimeFormat to format an calendar. This is used only when context is {@link #DATETIME_CONTEXT}.
	 *
	 * @return DefaultDatetimeFormat
	 */
	public DateFormat getDefaultDatetimeFormat() {
		return _defaultDatetimeFormat;
	}

	/**
	 * Sets DefaultDatetimeFormat to format an calendar. This is used only when context is {@link #DATETIME_CONTEXT}.
	 *
	 * @param defaultDatetimeFormat the new defaultdatetime format
	 */
	public void setDefaultDatetimeFormat(DateFormat defaultDatetimeFormat) {
		_defaultDatetimeFormat = defaultDatetimeFormat;
	}
}
